Analysis of morphing multilayer inflatable wings for hypersonic vehicle

Gabriele Bombaci



The present activity involved in the HYPMOCES program, taking place in the transport area of the Seventh Framework Programme for Research and Technological Development (FP7-TRANSPORT). It is focused on the development of a morphing new system to be implemented within a cabin escape system for passengers transportation in hypersonic aircrafts (DLR SpaceLiner).

The main objective is to enhance the maneuverability of the escape capsule thanks to released aerodynamic control surfaces increasing in turn the lifting and lateral stability, with the goal of bring the passengers back to ground (or water).

Morphing approach, in particular, allows the cabin escape system to adapt in real time to the unpredicted environment at desired flight performance, offering compliance to the multi-phase nature of reentry flights and has definitely the potential to increase safety for passengers in hypersonic flights through enhanced mission flexibility.

Focus in the present activity is given on the structural and thermo-mechanical design process of the inflatable subsystems taking part to the hypersonic morphing concept to be integrated within the cabin escape system. Different systems and approach are verified with Ls-Dyna to find a right design of the flexible TPS structure.

The final concept is based on a flexible TPS membrane, stowed into the capsule volume and instantly released for achieving the desired capsule shape, enhancing the flight efficiency.

Folded balloons are placed in between the capsule’s flexible TPS and the pressurized cabin, thereafter once the capsule is released from the mother spacecraft, a properly dimensioned gas generator pyrotechnically ignited, inflates the bags to a design pressure driving in turn the deployment of the flexible TPS from the folded to the nominal configuration, maintaining constant shape during flight.

The layout for the flexible TPS has been evaluated ensuring thermal protection capability, providing as well enough compliance for matching with balloons inflation.

The layout of flexible TPS is based on a multi-layer structure with an optimized layer setup creating a suitable thermal barrier. The multi- layer structure consists of many continuous layers of Nextel and Saffil, and some layers of discontinued Pyrogel blocks, this configuration is efficient from both, thermal and mechanical point of view. Also the ballons are realized with a multi-layer structure, made by Kapton and Zylon layers.